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Dive into the research topics where Ji Kon Ryu is active.

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Featured researches published by Ji Kon Ryu.


Modern Pathology | 2012

Consensus statement on the pathology of IgG4-related disease.

Vikram Deshpande; Yoh Zen; John K. C. Chan; Eunhee E Yi; Yasuharu Sato; Tadashi Yoshino; Günter Klöppel; J. Godfrey Heathcote; Arezou Khosroshahi; Judith A. Ferry; Rob C. Aalberse; Donald B. Bloch; William R. Brugge; Adrian C Bateman; Mollie N. Carruthers; Suresh T. Chari; Wah Cheuk; Lynn D. Cornell; Carlos Fernandez-del Castillo; David G. Forcione; Daniel L. Hamilos; Terumi Kamisawa; Satomi Kasashima; Shigeyuki Kawa; Mitsuhiro Kawano; Gregory Y. Lauwers; Yasufumi Masaki; Yasuni Nakanuma; Kenji Notohara; Kazuichi Okazaki

IgG4-related disease is a newly recognized fibro-inflammatory condition characterized by several features: a tendency to form tumefactive lesions in multiple sites; a characteristic histopathological appearance; and—often but not always—elevated serum IgG4 concentrations. An international symposium on IgG4-related disease was held in Boston, MA, on 4–7 October 2011. The organizing committee comprising 35 IgG4-related disease experts from Japan, Korea, Hong Kong, the United Kingdom, Germany, Italy, Holland, Canada, and the United States, including the clinicians, pathologists, radiologists, and basic scientists. This group represents broad subspecialty expertise in pathology, rheumatology, gastroenterology, allergy, immunology, nephrology, pulmonary medicine, oncology, ophthalmology, and surgery. The histopathology of IgG4-related disease was a specific focus of the international symposium. The primary purpose of this statement is to provide practicing pathologists with a set of guidelines for the diagnosis of IgG4-related disease. The diagnosis of IgG4-related disease rests on the combined presence of the characteristic histopathological appearance and increased numbers of IgG4+ plasma cells. The critical histopathological features are a dense lymphoplasmacytic infiltrate, a storiform pattern of fibrosis, and obliterative phlebitis. We propose a terminology scheme for the diagnosis of IgG4-related disease that is based primarily on the morphological appearance on biopsy. Tissue IgG4 counts and IgG4:IgG ratios are secondary in importance. The guidelines proposed in this statement do not supplant careful clinicopathological correlation and sound clinical judgment. As the spectrum of this disease continues to expand, we advocate the use of strict criteria for accepting newly proposed entities or sites as components of the IgG4-related disease spectrum.


Arthritis & Rheumatism | 2012

Recommendations for the nomenclature of IgG4-related disease and its individual organ system manifestations

John H. Stone; Arezou Khosroshahi; Vikram Deshpande; John K. C. Chan; J. Godfrey Heathcote; Rob C. Aalberse; Atsushi Azumi; Donald B. Bloch; William R. Brugge; Mollie N. Carruthers; Wah Cheuk; Lynn D. Cornell; Carlos Fernandez-del Castillo; Judith A. Ferry; David G. Forcione; Günter Klöppel; Daniel L. Hamilos; Terumi Kamisawa; Satomi Kasashima; Shigeyuki Kawa; Mitsuhiro Kawano; Yasufumi Masaki; Kenji Notohara; Kazuichi Okazaki; Ji Kon Ryu; Takako Saeki; Dushyant V. Sahani; Yasuharu Sato; Thomas C. Smyrk; James R. Stone

John H. Stone, Arezou Khosroshahi, Vikram Deshpande, John K. C. Chan, J. Godfrey Heathcote, Rob Aalberse, Atsushi Azumi, Donald B. Bloch, William R. Brugge, Mollie N. Carruthers, Wah Cheuk, Lynn Cornell, Carlos Fernandez-Del Castillo, Judith A. Ferry, David Forcione, Gunter Kloppel, Daniel L. Hamilos, Terumi Kamisawa, Satomi Kasashima, Shigeyuki Kawa, Mitsuhiro Kawano, Yasufumi Masaki, Kenji Notohara, Kazuichi Okazaki, Ji Kon Ryu, Takako Saeki, Dushyant Sahani, Yasuharu Sato, Thomas Smyrk, James R. Stone, Masayuki Takahira, Hisanori Umehara, George Webster, Motohisa Yamamoto, Eunhee Yi, Tadashi Yoshino, Giuseppe Zamboni, Yoh Zen, and Suresh Chari


Gut | 2013

Long-term outcomes of autoimmune pancreatitis: a multicentre, international analysis

Phil A. Hart; Terumi Kamisawa; William R. Brugge; Jae Bock Chung; Emma L. Culver; László Czakó; Luca Frulloni; Vay Liang W. Go; Thomas M. Gress; Myung-Hwan Kim; Shigeyuki Kawa; Kyu Taek Lee; Markus M. Lerch; Wei-Chih Liao; Matthias Löhr; Kazuichi Okazaki; Ji Kon Ryu; N. Schleinitz; Kyoko Shimizu; Tooru Shimosegawa; Roy Soetikno; George Webster; Dhiraj Yadav; Yoh Zen; Suresh T. Chari

Objective Autoimmune pancreatitis (AIP) is a treatable form of chronic pancreatitis that has been increasingly recognised over the last decade. We set out to better understand the current burden of AIP at several academic institutions diagnosed using the International Consensus Diagnostic Criteria, and to describe long-term outcomes, including organs involved, treatments, relapse frequency and long-term sequelae. Design 23 institutions from 10 different countries participated in this multinational analysis. A total of 1064 patients meeting the International Consensus Diagnostic Criteria for type 1 (n=978) or type 2 (n=86) AIP were included. Data regarding treatments, relapses and sequelae were obtained. Results The majority of patients with type 1 (99%) and type 2 (92%) AIP who were treated with steroids went into clinical remission. Most patients with jaundice required biliary stent placement (71% of type 1 and 77% of type 2 AIP). Relapses were more common in patients with type 1 (31%) versus type 2 AIP (9%, p<0.001), especially those with IgG4-related sclerosing cholangitis (56% vs 26%, p<0.001). Relapses typically occurred in the pancreas or biliary tree. Retreatment with steroids remained effective at inducing remission with or without alternative treatment, such as azathioprine. Pancreatic duct stones and cancer were uncommon sequelae in type 1 AIP and did not occur in type 2 AIP during the study period. Conclusions AIP is a global disease which uniformly displays a high response to steroid treatment and tendency to relapse in the pancreas and biliary tree. Potential long-term sequelae include pancreatic duct stones and malignancy, however they were uncommon during the study period and require additional follow-up. Additional studies investigating prevention and treatment of disease relapses are needed.


Gastrointestinal Endoscopy | 2009

Palliative treatment with self-expandable metallic stents in patients with advanced type III or IV hilar cholangiocarcinoma: a percutaneous versus endoscopic approach.

Woo Hyun Paik; Young Soo Park; Jin-Hyeok Hwang; Sang Hyub Lee; Chang Jin Yoon; Sung-Gwon Kang; Jae Kyung Lee; Ji Kon Ryu; Yong-Tae Kim; Yong Bum Yoon

BACKGROUND AND OBJECTIVE Endoscopic or percutaneous biliary drainage with self-expandable metallic stents (SEMS) is widely used for the palliation of cholestasis in patients with advanced hilar cholangiocarcinoma. However, little is known about which is the better option in patients with advanced hilar cholangiocarcinoma. We compared the clinical outcomes of these 2 methods of biliary decompression in these patients. DESIGN AND SETTING Multicenter retrospective study. PATIENTS A total of 85 patients with newly diagnosed advanced hilar cholangiocarcinoma (Bismuth III or Bismuth IV) and who did not receive an operation, chemotherapy, or radiotherapy were retrospectively reviewed. Forty-four of the 85 received endoscopic SEMS and 41 received percutaneous SEMS. INTERVENTIONS Endoscopic SEMS or percutaneous SEMS. MAIN OUTCOME MEASUREMENTS AND RESULTS Baseline characteristics were similar in the 2 groups, but the rate of successful biliary decompression was significantly higher in the percutaneous SEMS group than in the endoscopic SEMS group (92.7% vs 77.3%, respectively, P= .049). Overall rates of procedure-related complications were similar for the 2 groups, but 1 death (from biliary sepsis) occurred in the endoscopic SEMS group. Median survival of patients in whom biliary drainage was successful initially, regardless of which procedure was performed, was much longer than that of patients who had failed biliary drainage (8.7 months vs 1.8 months, respectively, P< .001). Once successful biliary decompression had been achieved, median survival and stent patency duration were similar in the 2 study groups. LIMITATION Retrospective study. CONCLUSIONS Percutaneous SEMS may be chosen for initial biliary drainage in patients with advanced type III or IV hilar cholangiocarcinoma, given higher initial success rate and low level of procedure-related cholangitis.


Annals of Surgery | 2009

Differential Diagnostic and Staging Accuracies of High Resolution Ultrasonography, Endoscopic Ultrasonography, and Multidetector Computed Tomography for Gallbladder Polypoid Lesions and Gallbladder Cancer

Jin-Young Jang; Sun-Whe Kim; Seung Eun Lee; Dae Wook Hwang; Eun Jung Kim; Jae Young Lee; Soo Jin Kim; Ji Kon Ryu; Yong Tae Kim

Objective:The authors undertook to investigate the diagnostic performance of high-resolution ultrasound (HRUS), and to compare the differential diagnostic and staging accuracies of endoscopic ultrasonography (EUS), HRUS, and multidetector computed tomography for gallbladder (GB) polypoid lesions and GB cancer. Summary of Background Data:Endoscopic ultrasonography was considered the most sensitive diagnostic modality for GB polypoid lesions. However, recent technical advancements in other image modalities including conventional sonography (US) allow the production of comparable images. Methods:A total of 170 patients, with a more than 1-cm sized polypoid GB lesion, and without evidence of definite local invasion to adjacent organs during primary screening, were consecutively enrolled in this prospective, blind, comparative study. After excluding 26 patients with inappropriate medical histories, 144 patients were finally enrolled. All patients underwent surgical resection. Clinical diagnoses were compared with histopathologic findings by diagnostic modality. Results:Of the 144 patients, there were 115 (79.8%) cases of benign GB polypoid lesions and 29 (20.2%) cases of GB cancers. Diagnostic sensitivities for malignancy were 90% for HRUS, 86% for EUS, and 72% for CT. When evaluating the abilities of these modalities to predict GB cancer depth of invasion, we excluded 2 unusual GB malignancies (melanoma and lymphoma), HRUS was found to have the highest diagnostic accuracy of 62.9%; EUS and CT had accuracies of 55.5% and 44.4%, respectively. Conclusions:The diagnostic accuracies of HRUS and EUS for the differential diagnosis of GB polypoid lesions were comparable. In view of patient comfort and no requirement for sedation, we consider that HRUS is likely to become an important diagnostic modality for the differential diagnosis and staging of GB polypoid lesions and early GB cancer.


Liver Transplantation | 2009

Endoscopic treatment for biliary stricture after adult living donor liver transplantation

Jeong Kyun Seo; Ji Kon Ryu; Sang Hyub Lee; Joo Kyung Park; Ki Young Yang; Yong-Tae Kim; Yong Bum Yoon; Hae Won Lee; Nam-Joon Yi; Kyung-Suk Suh

Endoscopic intervention is considered to be the primary treatment for biliary stricture after adult living donor liver transplantation (LDLT) with duct‐to‐duct biliary reconstruction. The aim of this study was to investigate the risk factors of biliary stricture and the clinical outcomes and predictors of failure after endoscopic retrograde cholangiography with balloon dilation (ERC‐D). We enrolled 239 adult patients who underwent LDLT between 2000 and 2006. Sixty‐eight patients (28.4%) developed biliary stricture. Twenty‐nine patients with anastomotic biliary stricture were treated with ERC‐D and stenting. We retrospectively analyzed the risk factors of biliary stricture and the clinical outcomes of ERC‐D. The median follow‐up period was 31 months. The risk factors of biliary stricture on multiple logistic regression analysis were a graft with multiple bile ducts, a previous history of bile leakage, and hepatic artery stenosis. The overall success rate of ERC‐D was 64.5%. On simple logistic regression, the failure of primary ERC‐D was associated with late biliary stricture over 24 weeks and more than 8 weeks between a 2‐fold increase of serum alkaline phosphatase from the stable level and ERC‐D, even though these were not statistically significant on multiple logistic regression. The relapse rate of stricture after successful ERC‐D was 30%. The duration of stenting in the recurrence group was shorter than that in the nonrecurrence group (11.8 ± 5.03 versus 29.0 ± 11.6 weeks, P = 0.004). ERC‐D is effective for the management of anastomotic biliary stricture. However, the failure rate of primary ERC‐D may be high in patients with late onset and delayed diagnosis of biliary stricture. The recurrence seems to occur frequently in patients with a short duration of stenting. Liver Transpl 15:369–380, 2009.


Pancreas | 2008

Review of 67 patients with autoimmune pancreatitis in korea: A multicenter nationwide study

Ji Kon Ryu; Jae Bock Chung; Seung Woo Park; Jong Kyun Lee; Kyu Tack Lee; Woo Jin Lee; Jong Ho Moon; Kwang Bum Cho; Dae Whan Kang; Jin Hyeok Hwang; Kyo Sang Yoo; Byung Moo Yoo; Don Hang Lee; Hae Kyung Kim; Young Soo Moon; Jin Lee; Hong Sik Lee; Ho Sun Choi; Sung Koo Lee; Yong-Tae Kim; Chang Duck Kim; Sun Joo Kim; Joon Soo Hahm; Yong Bum Yoon

Objectives: The ideal diagnostic criteria of autoimmune pancreatitis (AIP) are still challenging. Therefore, we investigated the clinical features of AIP in Korea and assessed the clinical use of new Korean diagnostic criteria. Methods: We reviewed 67 patients with AIP enrolled in 16 hospitals via a multicenter study. The diagnosis was confirmed according to the Korean diagnostic criteria that included pancreatic imaging, laboratory findings, histopathology, and response to steroid. Results: Mean age of the patients was 56 years, and 73% were men. Obstructive jaundice (52%) was the most common symptom, and 14 patients (21%) had other organ involvement. Fifty-four patients (81%) revealed diffuse swelling of the pancreas. Either immunoglobulin (Ig)G or IgG4 was elevated in 76%. According to the Korean criteria, 65 patients had definite diagnostic criteria, and 2 patients had probable criteria. Fifteen patients were fulfilled with image, serological, and histopathologic criteria, and 4 patients could be diagnosed with image and steroid responsiveness. Ten patients experienced recurrent attacks of AIP during the mean 20-month follow-up. Conclusions: Among 67 cases of AIP, either IgG or IgG4 was elevated in 76% of patients, and 14 patients (21%) had other organ involvement. New Korean diagnostic criteria are useful for diagnosis of AIP.


Pancreas | 2008

Survival and prognosis of invasive intraductal papillary mucinous neoplasms of the pancreas: comparison with pancreatic ductal adenocarcinoma.

Sang Myung Woo; Ji Kon Ryu; Sang Hyub Lee; Ji Won Yoo; Joo Kyung Park; Yong-Tae Kim; Yong Bum Yoon

Objectives: Invasive intraductal papillary mucinous neoplasm (IPMN) of the pancreas is often considered to have a better prognosis than pancreatic ductal adenocarcinoma. The aim of this study was to evaluate and compare the prognosis and clinicopathologic features between 2 groups. Methods: Clinicopathologic features and long-term outcome of 32 patients with invasive IPMN were retrospectively evaluated and compared with those of 332 patients with pancreatic ductal adenocarcinoma. Results: Asymptomatic patients were more frequently observed in the group of invasive IPMN than ductal adenocarcinoma (28% vs 11%, P = 0.013). The distribution of stages of invasive IPMN was as follows: stage I (n = 10, 31%), II (n = 8, 25%), III (n = 3, 9%), and IV (n = 11, 34%). Among 19 patients who underwent resection for invasive IPMN, 10 (53%), 1 (5%), 1 (5%), and 2 (11%) had T1 stage tumors and tumor with lymph node metastasis, lymphatic, and perineural invasions, respectively, which were significantly infrequently observed compared with those with ductal adenocarcinoma. The 5-year survival rate of invasive IPMN was 33.9% compared with 9% of ductal adenocarcinoma (P = 0.011). The difference in the mean survival rates between invasive IPMN and ductal adenocarcinoma in patients without metastasis was also significant but not in patients with metastasis. During the median follow-up period of 18.4 months, 3 patients (16%) had a recurrence after resection for invasive IPMN. Conclusions: Both the less aggressive pathological factors concerned with tumor invasiveness and early diagnosis of invasive IPMN contribute to higher survival rates of invasive IPMN than ductal adenocarcinoma. However, the prognosis of metastatic invasive IPMN is as poor as that of ductal adenocarcinoma.


Cancer Letters | 2001

Genetic alterations in gallbladder adenoma, dysplasia and carcinoma

Yong-Tae Kim; Jin Kim; Yoo Hyun Jang; Woo Jin Lee; Ji Kon Ryu; Yoon-Kyung Park; S.-W. Kim; Woo Ho Kim; Yong Bum Yoon; Chung Yong Kim

Adenoma and dysplasia in the gallbladder (GB) have been reported as precancerous lesions, but the genetic evidence of this is not clearly defined. The purpose of this study was to analyze the frequencies of K-ras, p53, and p16 gene mutations, of microsatellite instability (MI) and of loss of heterozygosity (LOH) in GB cancer, dysplasia, and adenoma. Tissues from 15 GB cancers, five dysplasias around cancerous tumors, and three adenomas were collected prospectively. The mutation rates of K-ras, p53, and p16 were 20.0, 35.7, and 30.7%, respectively, in GB cancers. However, no mutations were found in dysplasia or adenoma. Reduced staining for p16 was seen in 23% of carcinomas. All of the GB carcinomas and four out of five (80%) of the dysplasias showed LOH in a minimum of one locus, but one out of three (33%) cases of adenoma displayed LOH in only one locus. All of the loci of LOH in the dysplasias, except one, showed the same patterns of allelic loss as the adjacent carcinomas. Only one dysplasia showed multiple MI. In conclusion, multiple LOH may be associated with the development of dysplasia and the malignant transformation of GB carcinoma. Gene alterations of K-ras, p53, and p16 are important steps in the malignant changes of dysplasia. However, MI seems to have only a limited role in GB cancer development.


Pancreas | 2007

The efficacy of nonsurgical treatment of infected pancreatic necrosis.

Jun Kyu Lee; Kyeong Keun Kwak; Joo Kyung Park; Won Jae Yoon; Sang Hyub Lee; Ji Kon Ryu; Yong-Tae Kim; Yong Bum Yoon

Objectives: We conducted this study to evaluate the efficacy of nonsurgical treatment for patients with infected pancreatic necrosis (IPN). Methods: Among 224 patients with acute pancreatitis from 2000 to 2004, there were 31 patients diagnosed as having IPN complication. The diagnostic criteria for IPN were either a positive culture or free gas in the pancreas of patients with acute pancreatic necrosis. Nonsurgical management including percutaneous drainage or endoscopic drainage (ED) followed by vigorous irrigation was initially attempted in all patients. Surgery was planned only when there was no clinical improvement after the initial nonsurgical treatment. Results: Percutaneous drainage or ED was performed in 18 and 5 patients, respectively. Eight patients received antibiotics only. Four patients (12.9%) (3 from percutaneous drainage group and 1 from ED group) required surgery. Sepsis or fistula developed in 32% and 6% of patients, respectively, and was managed successfully. One patient (3.2%) died as a result of rapidly progressing multiorgan failure. The mean duration of hospitalization was 37 days. During the follow-up period, 7 patients were readmitted because of fever; they were managed by reposition of the drainage tube. Conclusions: Intensive nonsurgical treatment is very effective and safe and should be considered as an initial treatment modality for patients with IPN.

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Yong-Tae Kim

Seoul National University Hospital

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Sang Hyub Lee

Seoul National University Hospital

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Yong Bum Yoon

Seoul National University

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Joo Kyung Park

Seoul National University

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Yong Tae Kim

Korea Institute of Science and Technology

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Sang Myung Woo

Seoul National University

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Jin Myung Park

Seoul National University

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